In message <199511211516.HAA03113@rock.west.ora.com>, Terry Allen writes:>Dan and I gave different answers to the question of whether an>HTML document may have a prepended SGML declaration. Dan pointed to>the following passage in RFC 1866:>>| 3.3. HTML Public Text Identifiers>| >| To identify information as an HTML document conforming to this>| specification, each document must start with one of the following>| document type declarations.>| >| <!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">>>and I had in mind ISO 8879 4.283:>>"SGML document entity: The SGML entity that begins an SGML document>[as distinguished from SUBDOCs and text entities]. It contains, >at a minimum, an SGML declaration, a base document type declaration,>and the start and end (if not all) of a base document element."

See also: 6.2.3 "Implied SGML Declaration"

... the system can imply the SGML declaration ...

>It is not possible to override 4.283 in the HTML spec;

It is possible, and we did it. It's called an application convention.
Just like null end-tags and all that. I don't understand your point.